This invention relates to a culture vessel for use in culturing plants.
Recently the so-called culture in which bacteria, tissue cells and the like are divided and propagated, is popular. Specifically the culture of cells, which is called tissue culture, cultivates cell groups or tissue pieces. This culture requires media, and various vessels are used to contain the media.
An exemplary vessel for this purpose is a triangular flask of transparent glass as shown in FIG. 12. A medium (b) is put into the flask, and then tissue pieces are placed on the medium. For the prevention of the intrusion of bacteria into the flask, the flask is covered by aluminium foil (c) as shown in FIG. 12(A), or is filled with a cotton plug (d) as shown in FIG. 12(B) or with a silicone plug (e) as shown in FIG. 12(C).
In addition, as shown in FIG. 13, another exemplary vessel is a deep rectangular sectional box (f) of a thick plastic with a shallow cover (g). A medium is put into the box (f), and then tissue pieces are placed on the medium to be cultivated.
However, the above-described conventional triangular flask (a) has the following problems. That is:
(1) The flask (a) has a small mouth and is deep, and the level of a medium in the flask is accordingly low. When the medium is divided, a pincette, for example, has to be reached deep into the flask down to the level of the medium. When it is not well manipulated, the medium scatters to soil the interior of the flask.
(2) When tiny plant tissue pieces are put in, it is difficult to lay them in the same direction, and the manipulation is not efficient.
(3) When a cultured substance which has grown in the flask is transplanted into another vessel, it has to be picked up from the deep bottom of the flask, and the cultured substance can be easily damaged.
(4) Morphological abnormalities, retarded growth, and lowered ratio of tissues settling and growing tend to take place due to excessive water.
In the case of the flask covered with aluminium foil, when the fluid media contact the aluminium foil, withering takes place from the portions which have contacted the aluminium foil.
Compared with the triangular flask described above, the vessel shown in FIG. 13 is less inconvenient, but as far as it is a deep vessel, it cannot overcome the problems (1) to (3) discussed above. In addition, the box (f) has a double-structure at the upper portion on which a cover (g) is put on. This portion has far less transmission of direct lights (l), which are essential to the growth of plants. Such adversely reduced light transmitting area is an additional drawback to the culture vessel.
Furthermore, the above-described two conventional culture vessels do not allow the culturing states of a substance being cultured therein, its germinating and growing states, presence of contaminations, etc. to be visually observed in detail easily. When the vessels are stacked in a plurality of layers, it is harder to visually observe the interiors of the vessels.
In order to provide the above-described vessels with ventilation plugs, ventilation holes are formed in the covers of the vessels, and the ventilation plugs are filled in the ventilation holes so as to ventilate the interiors of the vessels. However, the problems with these plugs are that when the plugs are subject to the vapor pasteurization, they absorb the vapor and then shrink, depending on their materials, and become inoperative any more as the ventilation plugs, and furthermore the water intrudes into the vessels eventually to affect the plant cells therein. Taking into consideration the above-described problems, this invention has been made, and an object of this invention is to provide a culture vessel which facilitates the manipulation of laying in the vessel a substance to be cultivated, such as plant tissue pieces or others, and which allows its interior to be observed accurately even when a plurality of the vessels are stacked.